The epidemiological study described in this proposal is based on nearly 1000 interviews of mothers of randomly sampled children ages 1 to 10. Extensive data were collected with regard to the children's emotional and behavioral problems and competencies, children's health histories, child rearing and other family structure and environmental variables. In addition the original multistage sampling plan resulted in the selection of neighborhoods (primary sampling units) representing a broad range of community environments. Follow-up interviews of both mothers and children will be carried out when the children are ages 8 to 17 and again one year later. The measures of psychopathology will include DSM III based diagnostic interviews as well as scales derived from the original interviews. The data will be employed to determine the prevalence and persistence of psychiatric disorders in children. In addition the antecedents of these disorders in the problems of early childhood and the relative merits of diagnoses as compared to scaled measures of psychopathology will be assessed. Data collected at all three points in time will be employed to determine risk factors and concomitants of psychopathology. In addition, and relatively uniquely, the study will assess the generality of these risk factors and their relative potencies for children living in different extra-familial environments. The data analysis will include replication of previous findings suggesting differential environmental effects and test some theoretically derived hypotheses regarding their origins. This will be the first American study in which the prevalence and persistence of objectively defined DSM III psychiatric disorders in treated and untreated children will be determined. This knowledge is essential not only for prediction of disorders but also for prevention and treatment efforts.